Description: Publication date: Available online 16 September 2015 Source: FEBS Open Bio Author(s): Vivian H. Tang, Geoffrey A. Stewart, Barbara J. Chang A 14 kDa protein homologous to the γ-D-glutamyl-L-diamino acid endopeptidase members of the NlpC/P60 Superfamily has been described in Dermatophagoides pteronysssinus and D. farinae but it is not clear whether other species produce homologues. Bioinformatics revealed homologous genes in other Sarcopteformes mite species ( Psoroptes ovis and Blomia tropicalis ) but not in Tetranychus urticae and Metaseiulus occidentalis. The degrees of identity (similarity) between the D. pteronyssinus mature protein and those from D. farinae , P. ovis and B. tropicalis were 82% (96%), 77% (93%) and 61% (82%), respectively. Phylogenetic studies showed the mite proteins were monophyletic and shared a common ancestor with both actinomycetes and ascomycetes. The gene encoding the D. pteronyssinus protein was polymorphic and intronless in contrast to that reported for D. farinae . Homology studies suggest that the mite, ascomycete and actinomycete proteins are involved in the catalysis of stem peptide attached to peptidoglycan. The finding of a gene encoding a P60 family member in the D. pteronyssinus genome together with the presence of a bacterial promotor suggests an evolutionary link to one or more prokaryotic endosymbionts.